Human papillomavirus co-infection and survival in oral and oropharyngeal squamous cell carcinoma: A study in 235 Brazilian patients.

Abstract Objectives While unknown for oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC), some studies assessing cervical carcinoma have shown that human papillomavirus (HPV) co-infection can be associated with its prognosis. Methods Through in situ hybridization (HPV and Epstein-Barr virus [EBV] probes) and immunohistochemistry (p16INK4a, cyclin D1, p53, and Ki-67 antibodies), 126 OPSCC and 109 OSCC samples were assessed. Results All patients were EBV-negative. OPSCC (25%) showed a significant association with HPV compared to OSCC (11%). Almost all HPV-associated cases were p16INK4a-positive. Regarding OPSCC and OSCC, 23 and 7 cases were positive for high-risk HPV (HRHPV) only, 6 and 3 cases for low-risk HPV (LRHPV) only, and 3 and 2 cases for HRHPV/LRHPV, respectively. HPV-associated carcinomas showed a significantly higher proliferative index than HPV-unassociated carcinomas. Both carcinomas showed a similar overall survival rate, which was not affected by the HPV status. However, when comparing HPV-associated subgroups, patients with HRHPV/LRHPV-associated carcinomas showed worse survival. Conclusion LRHPV-associated and HRHPV/LRHPV-associated cases can also be detected when assessing OSCC and OPSCC. Further studies, especially in populations with a high prevalence of HPV-associated OPSCC, are necessary to understand the clinicopathological behavior of these neoplasm subgroups.